import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 高生平
 * Date: 2025-09-05
 * Time: 19:30
 */
public class Test {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int num = sc.nextInt();
        boolean prime = true;//先默认是素数，如果不是再改成false
        for (int i = 2; i <= Math.sqrt((double) num) ; i++) {
            if (num % i == 0) {
                prime = false;
            }
        }
        if (prime == true) {
            System.out.println(num + "是素数");
        } else {
            System.out.println(num + "不是素数");
        }
    }
}
